VR1600v firmware upgrade

I keep getting a [DNS: Device is vulnerable to attacks] message from my Anti-Virus software.It recommends that I backup my modem's current firmware to my laptop and download a firmware upgrade.I go to the [www.tp-link.com] website but there is no option to backup my modem's current firmware.I also cannot find a firmware upgrade to download for my modem.Can you advise on this?